Abstract

In this study, we (i) identified why Vietnamese shrimp fishers land juvenile fish illegally; (ii) identified groups of fishers that would use abycatch reduction device (BRD) to exclude these fish; (iii) studied the hydrodynamic performance of a juvenile and trash excluderdevice (JTED) in a flume tank; and (iv) assessed the performance of this device under commercial fishing conditions. Based on theresponses of 65 fishers to a questionnaire, we found that juvenile fish are now an important economic component of the totalcatch, and that fishers operating larger boats were more willing to use a JTED to exclude these fish than fishers operating smallerboats. The hydrodynamic study of a JTED identified the location of low-velocity regions around the device and codend, and this informationcan be used to identify the location of a secondary BRD to allow more fish to escape. The at-sea assessment of this devicefound that 73% of juvenile fish, 16% of valuable fish, and 8% of shrimp were excluded by the JTED, although most valuable fish andshrimp were smaller than the minimum legal landing size. Overall, this loss represents a 9% reduction in revenue. Yield-per-recruitanalysis indicated that this could be offset by not catching fish less than the minimum legal landing size.